Shackles have long been used in automotive, marine, aviation, and other fields to attach chains, cables, and ropes to a vehicle. One traditional shackle is a metal loop, usually U-shaped, closed by a bolt or pin that secures the shackle to a pair of mounting dogs on a vehicle. Metal shackles, while effective, carry certain inherent shortcomings. For example, they are heavy and tend to rattle and clank around on a vehicle when not in use, which is the majority of the time. They are also cumbersome to store when removed from the vehicle.
More recently, shackles made of a length of very strong rope have become popular and are generally referred to as rope shackles. A rope shackle generally comprises a relatively short length of rope with a tight knot at one end and an eyelet formed at the other. The length of rope can be threaded through an attachment structure on a vehicle and the knot pressed through the eyelet to form a loop. Other towing devices such as recovery ropes for instance, chains, or cables can be attached to the looped rope shackle. Rope shackles are a fraction of the weight of a traditional metal shackle, do not rattle when not in use, can be far more economical than metal shackles, and are convenient to store when not attached. Further, the breaking strength of rope shackles made of modern high strength fibers can exceed that of metal shackles of a corresponding size.
One issue faced by users of rope shackles is how best to attach them to various structures of a vehicle in such a way that they retain their integrity and strength but can be removed easily if desired. Metal shackles are attached with shackle pins that extend through the shackle and through aligned holes in mounting structures on a vehicle. They are removed by simply removing the shackle pin. Shackle pins also can be used to attach rope shackles, but this creates a very tight bend in the rope when a pulling force is applied, which can cause stress and breakage. Many users such as off-road vehicle drivers find themselves attaching a rope shackle to a traditional metal shackle, which defeats much of the advantage of rope shackles in the first place. Plus, locations on the vehicle to which the rope shackle can be attached generally are limited to the mounting positions for traditional shackles or metal D-rings.
A need exists for a method and device usable to attach a rope shackle to a vehicle in a safe and simple way, to allow its easy removal when desired, to provide for attachment locations in addition to the traditional D-ring mounting structures, and to reduce physical stress in the rope. It is to the provision of such a method and apparatus that the present invention is primarily directed.